Although highly-active anti-retroviral therapy (HAART) successfully reduces viral load in HIV and dramatically increases life expectancy, HIV-infected (HIV-positive) patients are at higher risk for chronic progressive medical conditions including HIV-associated dementia. Since HIV-positive patients tend to develop these conditions sooner than HIV-uninfected (HIV-negative) individuals, it has been hypothesized that the presence of the HIV virus accelerates end-organ senescence. Little is known, however, about premature brain senescence in HIV. Magnetic resonance imaging (MRI) has demonstrated structural brain abnormalities in older individuals without overt disease and in HIV-positive persons, even before frank cognitive and motor impairments emerge. However, the combined effects of the virus and age on the macro- and micro-structural characteristics of the brain have not been investigated. Chronic inflammation is thought to be a major contributor to age- and HIV-related structural brain changes. However, the role of inflammation in the combined effects of HIV and age on the macro- and micro-structure of the brain remains understudied. Further, although African Americans represent the largest proportion of those infected with HIV, and are at higher risk for chronic medical conditions associated with inflammation, few studies have directly compared racial differences in HIV-related brain abnormalities. Thus, the overall goal of this project is to investigate the combined effects of HIV, age and race on brain structure, to determine the role of inflammation in these effects, and to study the association of inflammation-related brain abnormalities in HIV to cognitive and motor impairments.